基于热重-质谱量化分析的矿渣解离-沉淀-自然碳化过程  

Quantitative Thermogravimetric-Mass Spectrometric Analysis of the Dissociation-Precipitation-Natural Carbonation Process of Granulated Blast Furnace Slag

作　　者：张哲 朱效宏[1,2] 吕昭秋 栾明昱 杨凯 ZHANG Zhe;ZHU Xiaohong;LYU Zhaoqiu;LUAN Mingyu;YANG Kai(College of Materials Science and Engineering,Chongqing University,Chongqing 400045,China;Department of Civil and Environmental Engineering,University of California Berkeley,Berkeley,CA 94720,United States)

机构地区：[1]重庆大学材料科学与工程学院,重庆400045 [2]加州大学伯克利分校土木与环境工程学院,美国CA 94720

出　　处：《硅酸盐学报》2024年第11期3554-3564,共11页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(52378218)。

摘　　要：水泥水化后所得到的是多相复合产物,仅采用热重法难以对重叠部分产物实现精准定量。采用热重-质谱联合技术对不同储存湿度条件、不同解离温度条件下的矿渣解离-沉淀-自然碳化过程进行研究,并对矿渣混凝土主要水化非晶产物C-(A)-S-H凝胶、碳化晶体产物CaCO_(3)等进行量化分析。结果表明:热重-质谱联用技术能准确剥离在热重分析时所得出的样品重叠峰(如C-(A)-S-H凝胶失水峰、不同晶型CaCO_(3)分解峰等),可有效降低样品在热重定量分析时所造成的物相重叠损失。Introduction:Thermogravimetry(TG)is widely used to evaluate the hydration process and the degree of reaction of cementitious materials.However,it is still challenging to accurately quantify the overlaps of hydration products using TG alone because cement hydration produce complex and multiphase composites.Mass spectrometry(MS)with its high specificity,sensitivity and fast testing speed,can promote TG quantification by eliminating overlapping decomposition peaks,further achieving the accurate quantification of cementitious hydration products.Therefore,this study designed the exposure conditions with different temperatures(5,20,and 40℃)and humidity levels(RH≈33%,RH≈59%,and RH≈95%)to study a dissolution process of the hydrated granulated blast furnace slag(GGBS).Hydration products at 6 different periods of dissolution(5,10,20,30,60 min,and120 min)were analyzed to assess the applicability and feasibility of the TG-MS coupling technique for quantifying the early reaction products of GGBS.Methods:Granulated blast furnace slag(GGBS)was used in dissolution-carbonation experiments,using deionized water and the 4mol/L NaOH solution as solvents.The liquid-solid ratio was 50:1,and the dissolution temperatures were set at 5,20℃,and 40℃.Three ambient relative humidity(RH)(33%,59%and 95%)were controlled using saturated Mg Cl_(2),NaBr,and KNO_(3)solutions.Mechanical stirring was performed at 750 r/min,and the vessel was covered with parafilm throughout the dissolution process.The samples were taken at 5,10,20,30,60 min,and 120 min.The precipitated products were hydration-stopped using the solvent-exchange method,followed by carbonation in a CO_(2)concentration of 600×10^(-6)for 28 d.Water and carbon dioxide were detected using a TG-MS system.Results and discussion:The C-(A)-S-H thermal decomposition mass loss in TG correlated well with the H_(2)O signal in the MS system under tested conditions,whereas the relation depends on degree of hydration.This phenomenon may be attributable to the following factors:on the one

关 键 词：矿渣 碳化分析 热重分析 质谱量化分析 

分 类 号：X757[环境科学与工程—环境工程] TQ172.1[化学工程—水泥工业]